MOF-derived porous graphitic carbon with optimized plateau capacity and rate capability for high performance lithium-ion capacitors

Abstract

The development of anode materials with high rate capability and long charge–discharge plateau is the key to improve performance of lithium-ion capacitors (LICs). Herein, the porous graphitic carbon (PGC-1300) derived from a new triply interpenetrated cobalt metal-organic framework (Co-MOF) was prepared through the facile and robust carbonization at 1300°C and washing by HCl solution. The as-prepared PGC-1300 featured an optimized graphitization degree and porous framework, which not only contributes to high plateau capacity (105.0 mAh·g⁻¹ below 0.2 V at 0.05 A·g⁻¹), but also supplies more convenient pathways for ions and increases the rate capability (128.5 mAh·g⁻¹ at 3.2 A·g⁻¹). According to the kinetics analyses, it can be found that diffusion regulated surface induced capacitive process and Li-ions intercalation process are coexisted for lithium-ion storage. Additionally, LIC PGC-1300//AC constructed with pre-lithiated PGC-1300 anode and activated carbon (AC) cathode exhibited an increased energy density of 102.8 Wh·kg⁻¹, a power density of 6017.1 W·kg⁻¹, together with the excellent cyclic stability (91.6% retention after 10000 cycles at 1.0 A·g⁻¹).